Air-heater.



S. T. WILLSON.

AIR HEATER.

APPLICATION FILED APR. 1!, 1916.

1 1 98, 982. Patented Sept. 19, 1916.

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mr NORRIS PEYERS can PnoI'O-unw wAsnINcwN. 0 cv SAMUEL TULLY WILLSON, OF BROOKLYN, NEW YORK.

AIR-HEATER.

Specification of Letters Patent.

Patented Sept. 19, 1916.

Application filed April 11, 1916. Serial No. 90,468.

' ing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Air- Heaters; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Thi invention relates to air heaters and has special reference to heaters for heating air for drying purposes, although it is to be understood that it is not limited in its utility to such association.

An object of the invention is to provide a heater embodying new and improved means for heating air as it is passed through the heater, and to absorb the maximum heat units in its passage.

A further object of the invention is to provide a heater of the general type of tubular boilers with improved means for forcing the air to be heated through such heater in a spiral path with exit at the hottest point in the heater.

A further object of the invention is to provide a heater having heat-radiating tubes with means for choking the tubes at the top to provide the maximum radiating surface with the minimum passage for the products of combustion.

\Vith these and other objects in view the invention consists in certain novel features of construction, combination and arrangement of parts as will be hereinafter more fully described and claimed.

In the drawings :Figure 1 is a view of the improved heater partly in side elevation and partly in diametrical section. Fig. 2 is a top view of the heater partly in plan and partly in horizontal section.

Like characters of reference designate corresponding parts throughout the several views.

The improved heater which forms the subject-matter of this application comprise a housing 10, here shown as cylindrical in form, of heat-insulating material, but it is to be understood that the exact form and construction of the housing forms no part of the present invention. Below the housing 10 a heating chamber 11 is provided with any means for supporting combustion within the chamber, here shown conventionally as a gaseous fuel burner 12. Also as shown the gaseous fuel burner 12 is connected with a removable and replaceable plate 13 by means of which the burner may be conveniently and Quickly dissociated from the heating chamber 11. Above the housing 10 a chamber 14 is provided, communicating with a flue 15.

The heating chamber 11 is separated from the housing 10 by a flue sheet 16, a similar flue sheet 17 being employed to separate the housing 10 from the chamber 14. Extending between the flue sheets 16 and 17 are a plurality of fiues 18 forming a passage from the chamber 11 to the chamber 14. Products of combustion from the burner 12 pass upwardly through the several flues 18 and the heat carried thereby is absorbed and radiated by such flues 18. As it is desirable that the tines 18 shall present a considerable amount of radiating surface, and that the products of combustion shall pass through such fiues slowly so that the heat may be absorbed by such fiues, choker blocks 19 are inserted at the upper ends of such flues, as

shown more particularly at Fig. 1, such choker blocks being provided with openings less in diameter than the diameter of the Hues.

An air inlet 20 is provided adjacent the top of the housing 10 positioned at a tangent as shown, so that the airintroduced through such opening 20 will circulate around the housing 10 and pass clownwardly in a spiral path to the outlet passage 21. The movement, however, is not direct from the opening 20 to the opening 21, but a battle plate 22 is extended across the greater portion of the housing 10, spaced slightly above the flue sheet 16 so that before reaching the outlet 21 all of the air must pass over the edge of the battle as indicated at Fig. 1 and come in contact with the flue sheet 16 and the lower end of the flues 18 which, being located immediately above the burner 12, are there heated to the greatest degree of heat. It is well known, that the tendency of heated air is to rise so that the air is forced downwardly from the inlet 20 to the outlet 21 against such tendency, and therefore remains in the heater the greatest possible time before it is forced out of the outlet 21. It is obvious that the air must be forced through the heater either by actual mechanical means or by mechanical means ,forming an induced draft so that the external atmospheric air Will force the air through such heater.

I claim 1. The combination with a cylindrical housing, of fiues passing longitudinally through the housing, a heating unit discharging products of combustion through the fines, means to introduce tangentially air into the housing at one end, means to bring the air into contact With the hottest surface of the fines, and means to Withdraw the air at the other end .of said housing contiguous to such hottest surface.

2. The combination with a housing, of fines passing through the housing, a heating unit positioned to discharge products of combustion through the flues, means to introduce air tangentially into the housing and to follow a spiral path Within the housing, means to bring the air into contact with the hottest surface of the heater, and means to Withdraw the air contiguous to such hottest surface.

3. The combination of a housing, a plurality of fines extending through the housspirally about the flues, means to cause the air to come in contact With the hottest surface portions of said flues near the heater, and means to Withdraw the air adjacent to such hottest surface.

4. The combination of a housing, a plurality of fines extending through the housing, a burner discharging products of combustion through the fiues, chokers in the flues adapted to reduce the area of the fines at the point so choked, means to introduce air tangentially into the housing to pass spirally about the fiues, means to cause the air to come in contact with the hottest surface portions of the fiues and heater, and means to Withdraw the air.

In testimony whereof I affix my signature.

SAMUEL TULLY WVILLSON.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

